feat: implement Security Timeline View (#156)

[RUKAYAT-CODER]

Summary

Implements the Security Timeline View as specified in issue #156, providing chronological visibility into security events with grouping and filter support.

Changes

• SecurityTimelineView.tsx - React component with chronological event list (newest first), severity filter, and group filter
• SecurityTimelineView.css - Dark-theme styles consistent with existing dashboard components
• SecurityTimelineView.spec.tsx - Tests covering render, chronological ordering, severity filter, group filter, empty state, and default props

Acceptance Criteria

• Timeline implemented and events displayed chronologically
• Events ordered correctly (newest first)
• Filters supported (by severity and by group)

closes #156

[mijinummi]

Hi @RUKAYAT-CODER thanks for your contributions, please kindly fix the remaining ci failures. Well done for the effort you have put so far on this.

[RUKAYAT-CODER]

Hi, @mijinummi . Fixed all CI failures related to this PR. The Docker and TypeScript type-check failures are pre-existing on main and not caused by my changes.

[mijinummi]

Hello @RUKAYAT-CODER , please pull from main the latest changes, and make a push again. Thank you

[RUKAYAT-CODER]

Pulled from the main and pushed again.
Done

[RUKAYAT-CODER]

Fixed the errors